DARPA program sets distance record for power beaming
(darpa.mil)75 points by gnabgib 13 hours ago
75 points by gnabgib 13 hours ago
＂maximum impact of atmospheric effects＂ would be simply a foggy day...
There’s no range in Florida large enough for this test otherwise I’m sure they would have.
Even Eglin wouldn’t be large enough.
Humidity would most likely attenuate the beam from 20% end to end to less than 1% - water vapour absorbs energy like nobody’s business.
This is a tech for arid environments - which seem to be where the US does most of its deployments these days.
The application to drones seems most clear: beam drones some extra power as needed. Or continually!
I wonder how big that receiving apparatus is. Whether the receiver is gimballed, or whether the drone itself has to fly a heading to aim at the sender: TBD.
Why not just beam power down the optical fiber? Optical fiber is exceptionally clear and works in fog and rain
Fiber transmits light, not rf. To get power out of fiber optics you have to have a photovoltaic cell on the other side and there's a limit for how much those can produce with such a collaminated light source.
Using fiber optics for power is like trying to make a solar panel generate electricity from a laser beam.
just have a tiny steam turbine equivalent...? (some thermoelectric generator) You don't really need to be efficient. You have fans to blow air and dissipate heat on the other end after all
Last time I forgot sunscreen at a UV index of 10 my skin started peeling of after half an hour so...
How about drones with a solar panel case? Would require a sunny day to work at all though.
Tiny nuclear reactor?
How about drones with a solar panel case? Would require a sunny day to work at all though.
Tiny nuclear reactor?
"reflects onto dozens of photovoltaic cells arranged around the inside of the device which convert the energy back to usable power."
This is no different that what we were considering two decades ago for the space elevator competition. One of the problems with this approach is that as the photovoltaic cells heat up their overall efficiency decreases.
The key thing they aren't saying is how much power it took to "send" 800 watts 5.3 miles...
They mentioned that it was 20% efficient at a closer distance.
So likely much lower than that.
Wow that's a long way from the proposals for sending GW of microwave power from satellites.
I was thinking of"how much is enough" so they can power 'instruments'. I am also thinking of 'how can we use this tech to revive space-instruments (the next generation of 'Voyagers' may be equipped with such receivers?)
I also wonder how difficult/impossible would it be, and the 'throughput'. Assuming that you want to recharge a recon drone (or the 'next generation of Voyagers flying in space) that flies over XYZ area/country/etc. Would it take 1sec or 10seconds 'of beam', and the accuracy/waste/total amount one would have to 'dispense' in order to give that drone the X seconds of 'juice' to keep it running for 1000x X seconds of flight duration. And what about clouds/mist/rain/snow/birds/etc.
'Infinite energy' for a drone (I mean no dependency to come down to refuel) is a game changer.
Would that work with 'instruments buried underground? And at what depth? ('War of the worlds' scenario). Could someone bury a device, with only the receiver protruding from the ground, with a battery to keep it alive, and waiting to be activated by a satellite passing by giving it the "10 seconds beam" to fully charge it and.. (I am thinking of the recent drone-related incidents/attacks within Russia and Iran)(if you park a drone for 10 months, its battery will deplete, right?)(I don't have a drone, but batteries are batteries).
A second thought on the matter, can one 'program' the light to be also transferring data? Park the drones in <insert foreign territory>. No programming. In the middle of nowhere (no 4G-5G). You fly a satellite over it, beam down the 'juice' (together with the instructions - no interception of the transfer is possible). Someone finds it 'before', they only get the hardware but no info/intel.
"The possibilities are endless" (and so are the nightmares)
This seems very silly. It's either a death ray project in a fake mustache or somebody had earmarked a bunch of money that they had to spend before it expired.
This is kinda surprising to read. I’ve never known anyone who isn’t incredibly excited at least at the prospect of wireless energy transfers. If you can do 800 watts over 8 km, surely we can do 150 watts across 3 feet in the household, and MANY of our most important discoveries come from DARPA essentially being a black budget skunkworks team.
But much of the stuff DARPA does seems weird. It’s not about ideas with solid foundation and thorough engineering, it’s about crapshoots that might work and would pay off in some way - often any financially feasible way.
They once put “cats” on guns in hopes it would surprise opponents even just for a quarter second, giving your spec ops dudes the advantage. They tried to create angled guns that could shoot around corners like 20 years ago. All kinds of crazy stuff! It would be a lot of fun to work there, I think.
> They tried to create angled guns that could shoot around corners like 20 years ago
The IDF got a gun that does this[0] into service in 2003.
The actual work is usually done by private companies under contract
The germans tried the curved gun with an attachment called Krummlauf during ww2. It would break after just a couple of magazines being fired. https://en.wikipedia.org/wiki/Krummlauf
Not sure how you would build one of those without the stress of the bullet during firing would not damage the barrel.
I'm amazed that worked for even one shot. Presumably gp was referring to cornershot or something similar, which seems like a much more reasonable approach.
“It’s a lot easier to send a power beam directly up or down relative to the ground because there is so much less atmosphere to fight through,” Jaffe explains. “For PRAD, we wanted to test under the maximum impact of atmospheric effects.”
Super impressive! My only complain is that this was done at the White Sounds desert in New Mexico, at over 1200 meters of elevation. For maximum impact they should have done it in Florida on a hot humid day